Is it possible to propagate and parameterize this connection?

I would like to parameterize these details. When I try to use Propagate Planar it says "Planar reference solids are parallel and do not define a connection." I manage to use Propagate Edge for a connection with additional board, but it doesn't create a connection between two solids but rather along all edges of all solids. Additionally I would like to parameterize these details for different slab thicknesses. Is this even possible with Bricscad?